Drive



Patented Mar. l2, 1940 I UNITED STATES PATENT orFlcE Application i5, No. 249,428

This applicationis a continuation in'part of my sewing machine for driving a needle bar I0. It prior application Serial No. 196,379, led March is to be distinctly understood, however, that the 17, 1938. novel drive is thereby not meant to be limited to The present invention relates to a novel drive operating a needle barin a sewing machine, as 5 for a reciprocatory and oscillatory element. said drive may be used with equal advantage in 5 It is the primary aim and object of the present any other type of mechanism which requires a invention to provide a mechanism for reciprocatvdrive betwe'en a rotary element and a reciprocaing an oscillatory element so that the same may tory and oscillatory element.

have a true harmonic motion in any direction in In Fig. 1, the reference numeral I I designates a its plane of oscillation and always reciprocate suitably driven shaft which is journalled in any 10 through the same distance. convenient manner at I2 and I3 in the conven- It is also among the objects of the present intional head Id of any sewing machine. More parvention to so devise the mechanism that rotary ticularly, the forward end I5 of the shaft II is motion is transformed into reciprocatory motion provided with a disc I6, having a projecting so that the rotary parts exert no side thrusts on crank pin I1 which rotatably supports a spur 15 the reciprocatory and oscillatoryelement, which gear I8. The spur gear I8 is in permanent mesh allows of short bearings for the element, elimiwith theinternal teeth 20 of a ring gear I9 whichV nates bending stresses in the element and makes is mounted in, or integral with, Ia member 26 that possible a compact and small overall design. is rotatably supported at 21 in the head I4 of the Before explaining in detail the present invenmachine and provides the bearing I2 for the 20 tion it is to be understood that the invention is shaft II.` The spur gear I8 is also provided with not limitedin its application to the details of an extending arm 22, receiving a stud or crank construction and arrangement of parts illuspin 23 which is connected with the needle bar I0. trated in the accompanying drawings, since the The needle bar Il! is guided at 24 for reciproca- 25 invention is capable of other embodiments and tion radially of theaxis of the ring gear I9 in a 25 of being practiced or carried out in various ways. cover 25 which is positioned on a cylindrical por- Also it is to be understood that the phraseology or tion 32 of the member` 26 and secured to the latterminology employed herein is for the purpose ter by screws 33 `for combined oscillation with of description and not of limitation, and it is said member 26. Hence, the Cover 25 with its not intended tolimit the invention claimed hereneedle bar guide 24 is oscillated together with 30 in beyond the requirements of the prior art. the ring gear I9. y

In the drawings: I The ratio between the teeth of the spur gear Fig. 1 is a. fragmentary, longitudinal section I8 and the internal gear I9 is one to two, and through a drive which embodies thepresent inthe stud 23 is spaced from the axis :cy-:1: of the vention. crank pin Il (Figs. l and 3) a distance which is 35 Fig. 2 is a fragmentary section taken substanexactly M1 the pitch diameter A (Fig. 3) 0f the tially on the line 2-2 of Fig. 1, certain elements internal gear |9- of the drive being shown in a different position Consequently, 0n rolling the spur gear I8y on of operation than in Fig. 1, however. the internal teeth 2li of the ring gear I9 through 40 Fig. 3 is an enlarged, fragmentary section 180 degrees of the latter and starting either at the 40 taken substantially on the line 3 3 of Fig. 1. position |811 or I8c in Fig. 3, the stud 23 will move Fig. 4 is a fragmentary elevation of a part of through a linear distance which is equal to the the construction shown in Fig. 1 as viewed in pitch diameter A of the ring gear I9. ,Moreover,

the direction of arrow 4 in Fig. 1. the stud 23 is bound to move in the linear path y Fig- 5 iS a fragmentary front elevation of a (Fig. 3) which is diametrical with respect to the 45 modied drive. ring gear I9, as will be readily understood. Fig. 6 is a section taken on the line 6-6 of Fig. 3 illustrates several 'momentary positions Fig. 5. of the spur gear I3 while the same rolls on the Fig. 6a is a diagrammatic view of a modied internal or ring gear I9 through 360 degrees of gearing usable in the drive shown in Figs. 5 the latter. In the home or starting position I8a 50 -and 6. i of the spur gear I8, the stud 23 is in its upper- Fig. 'l is a fragmentary section of another modmost position, assuming thereby that the needle iiied drive. bar IIl is to reciprocate vertically. Hence, the

The present invention is shown in the drawgear position Ita. in Fig. 3 corresponds to the ings. by way of example, as being embodied in a -position of the gear I8 as shown in Fig. 1. On 55 instance, the diametric line z (Fig. 3).

rolling the spur gear I8 on the internal gear 19 from the position I8a into the position I8b. the stud 23 will travel on the diameter y of the internal `gear I9 from the position 23a to the position 23h and the needle bar I Il will have completed one half of its downward or work stroke. On continued rolling of the spur gear I8 on the internal gear I9 from the position I8b into the position I8c, the stud 23 will continue to move on the same straight vline y to the position 23e in which the needle bar I0 assumes its lowermost position. On continued rolling of the spur gear I8 on the internal gear I8 from the position I8c into the position I8d in Fig. 3, the stud 23 will move reversely on the same straight line y into the position 23d, and the needle bar I0 will. ascend through the vertical distance between the stud positions 23e and 23d. On continued rolling of the spur gear I8 on the internal gear I9 from the position I8d into the starting position I8a, the stud 23 will move, on the same straight line y, from the position 23d to the starting position 23a in which the needle bar III is returned to its home or uppermost position.

It will now be understood that rotation of the drive shaft I I, and consequently of the crank pin I1, causes rolling ofthe spur gear I8 on the internal gear I9 and reciprocation of the needle bar Il). More particularly, one revolution of the shaft II result s in one complete reciprocation of the needle bar as will be readily observed in Fig. 3.

The needle bar I0 is reciprocated with a true harmonic motion on uniform rotation' of the crank shaft 11. VThis is due to the fact that the projection of the meshing engagement between4 gear I9 and gear I8, 'inany position o f the 'latter, upon the linear path of movement of the A stud 23 coincides with the corresponding positionr of said stud. Thisappearsclearly from the gear -positions I8a, I8b, I8c and I8d and their corresponding stud positions 23a, 23h, 23c and 23d in Fig. 3. l

In order to oscillate the needle bar, it is merely necessary to oscillate the rlng gear I9 together with the cover 25 with itsv needle bar guide 24., If the ring gear I 9 and the cover 25 are turned counter-clockwise (Fig. 3), gear I8 will also be rotated counter-clockwise, withthe result that the stud 23 will be moved inwardly from the pitch In other words, the stud 23 will not be at its extreme outward posidiameter of the ring gear.

tion. To place the stud 23 in the extreme outward'position, the disc I6 with the crank pin I1 must be rotated counter-clockwise (Fig. 3). Therefore, lthe diametric straight line on which the stud 23 will travel is then no longer the vertical line y but is inclined relative thereto as, for If the ring gear I9 and the cover 25 are turned slightly clockwise (Fig. 3) and then crank I1 rotated, it will be understood that the stud 23 travels lon a diametric straight line which'may be the line z' (Fig. 3), depending on the angle through which the ring gear I9 and the cover 25 have been Hence, for an oscillating groove 44 has two diametrically opposite groove portions 48 (one being shown in Fig. 5) which join two concentric groove portions 56 and 52 of different radii. The cam disc 46 may be rotated in any suitable manner at a one to two speed ratio with respect to the needle-bar reciprocating shaft II (Fig. 1) so that the needle bar III is laterally shifted for each reciprocation. It is to be distinctly understood, however, that the present invention is not limited to a needle bar which is laterally shifted for each reciprocation as it would not involve invention to substitute for the cam 46 in Fig. 4 other suitable means to cause a lateral shifting of the needle bar after a number of reciprocations of the same.

A modified drive, illustrated inFigs. 5 and 6, departs from the previously described drive primarily by substituting for the internal gear a spur gear and by drivingly connecting the crankoperated gear with said spur gear by means of an idler gear which is bodily rotating with said crank-operated gear. To this end, a crank 6II is provided with a sleeve 6I in' which is journaled coaxially of said sleeve a shaft 62 that carries at one end the spur gear 63. The sleeve 6I is itself journaled in a bearing 64 which is mounted in, or integral with, the overhanging head (not shown) of a sewing machine. Keyed-or otherwise secured to the free end of the sleeve 6I is a gear 65 which meshes with another gear 66 on a suitably driven shaft 61. Rotatably mounted on the crank 68' is another spur gear 68 which is drivingly connected with gear 63 by means of an Aidler gear 69, also rotatably mounted on the crank guide 14 for the needle bar. 'I'he guide member 12 is connected by a pin 15 or other suitable means with the free end vof shaft 62, wherefore the spur gear 63 and said guide member 12 are together oscillatable about the axis of shaft 62. Axial movementof the guide member 12 on 4its bearing surface 13 is prevented by a collar 16 thereon which retains said guide member in engagement with a machined shoulder 11 of the bearing 64. Axial movement of the sleeve 6I in bearing 64.is preventedpby a shoulder 18 of said sleeve andthe previously described gear 65 which are in engagement with the 'opposite ends, respectively, of said bearing 64. Axial movement of shaft 62 in the sleeve 6I is prevented due to its pin connection 15 with the axially immovable guide member 12. The guide member 12 has a laterally extending arm (Fig. 5) carrying a follower 8I that cooperates with a continuous cam groove 82 in a cam disc 83 which may be operated in the same manner as the previously described cam disc 46 in Fig. 4 in order to cause combined oscillation of the guide member 12 and spur gear 63.

As shown in Fig. 5, the guide or bearing 14 guides the needle bar for reciprocation radially of the gear 63, and inasmuch as the guide member 12 is journaled coaxially of the gear 63 the needle bar is guided for reciprocation radially of gear 63 inA any angular position of said guide member 12. The speed ratio between the gears 68 and l63 70 ,is two to one, and the pivot 'II on arm 18 is spaced from the axis of gear 68 a distance which is equal to that between the latter axis and the axis of gear 63.

Due to the specified speed ratio and spacing of u the pivot `ll from the axis of gear 68, (said pivot 1l is on rotation of the crank 60 reciprocated in a linear path which is diametrical with respect to gear 63. Moreover, the reciprocation of the pivot v'H is harmonic when the crank 66 is ro-` tated at uniform speed. This appears evident from a comparison between the illustrated crank positions 60a and 60h in Fig. 5 and an analysis of the component `motions of gear 68 vduring itsA movement from position 68a to position 68h. In

the assumed home position 68a of the -gear 68 (Fig. 5), the arm 'I0 is radially disposed with respect to gear 68 and the pivot 'Il is in the'` one dead center position lla. If the pin 'Il is to reciprocate harmonically in the linear path X-X (Fig. 5), the same must, for instance, be in coaxial alignment with gear 63 after a quarter revolution of the crank 60 from its home position 66a into the dot-and-dash line position 66h. Assume ing now that crank 60 were turned a quarter` revolution from the home position 60a into the dot-and-dash line position 60h without 'causing any rotation of gear 68 about its own axis, the arm 10 then would in the crank position` 60h assume the dotted line position 70x, i. e., 180 degrees displaced from the proper dot-and-dash line position 10b of arm 16. However, inasmuch as the speed ratio between the gears 68 and 63 is two to one and the idler gear 69 causes rotation of gear 68 about its own axis in a direction opposite to that of crank 60, gear 68 is rotated counter-clockwise (Fig. 5) through 180 degrees while the crank 60 is rotated clockwise through 90 degrees from the home position .60a into the dotand-dash line position 60h, with the resultthat arm 10 is in the proper position 10b when the crank is in the dot-and-dash line position 60h. Due to the above-explained spacing of the pivot H from the axis of gear 68, the former is furthermore located on the linear path X-X (Fig. 5), i. e., in coaxial alignment with gear 63, when the crank is in the dot-and-'dash line position 60h. In any other angular position of the crank 60, thpivot H is at a point in the linear path X--X which indicates harmonic motion of said pivot 1I if the crank is rotated at uniform speed. This is evidenced by the dot-and-dash line position 4llc (Fig. 5) of the pivot 1I when the crank assumes the dot-and-dash line position 66o. In this position, the radial line Y-Y of said crank, which passes through the axis of gear 68, intersects at Z the dot-and-dash line circle Z' the diameter of which is equal to the stroke X-X' of the pivot 1I and, hence, of the needle'bar l0, and the pivot position 'l lc coincides with the projection of said intersection point Z upon thel linear path X-X. Thus, the position of the pivot Il on the linear path X-X `coincides in every crank position with the projection upon said path X-X of the point of intersection between the circle Z and the radial line Y-Y of said crank, with the result that the pivot 1| and the needle bar I reciprocate with a true harmonic motion on uniform rotation of the crank 66.

On combined oscillation of the guide member 12 and gear 63 by the cam disc 83, or other suitable means, gear 68 is so rotated about its own axis that the pivot 'Il moves with the needle bar I6 so that the longitudinal axis 'of the latter always intersects the axis of gear 63. To amplify this, let it be assumed that the guide member 'I2 and the gear 63 are rotated counter-clockwise A degrees (Fig. relative to the crank 60 vin the position 60a so that the needle bar will be swung into a position in which its longitudinal axis co-A merdes with the dianetrical datand-dash une X"-X". During this counter-clockwise rotation or rocking motion of the guide member 12 and gear 63 through A degrees, gear 68 will be rotated counter-clockwise through B degrees (Fig.5) which equals 2A degrees due to the speed I ratio of two to one between the gears 68 and 63,

with the result that the arm on gear 68 will be rotated into the dot-and-dash line position Nid` (Fig. 5) in which the pivot 1l assumes the dotand-dash line position lid, i. e., a position on the new path of reciprocation X"-X" of the needle bar I8. On uniform rotation of the crank- 66 in either direction, the needle bar I0 will reciprocate with a trueV harmonic motion in the new path X"-X, as will be readily understood. Thus, in the absence of the specific cam disc 83 in Fig. 5,the needle bar i8 may be swung into any desired angular disposition for harmonic reciprocation in that disposition. It is also evident that the stroke of the needle bar is always the same irrespective of its direction of reciprocation.

While in the preceding description of the modiiled drive shown in Figs. 5 and 6 the gear 63 is twice the size of gear 68 and one idler gear 69 is interposed between the gears 63 and 68, it is not imperative that this modied drive be so constructed in order to operate the needle bar I0 in the specied manner. For instance, the gears 68 and 63 may be of equal size or other combination as long as the ratio o! two to one is maintained, as indicated diagrammatically at 68x and 63a: in Fig. 6a, in which case two coaxial gears 69a and 6917, which are together rotatable about their common axis and are rotatably mounted on the crank 603:, mesh with the gears 63a: and 682:, respectively. V

Fig. 7 discloses another modification of the drive which departs from that shown in Figs. 5 and 6 by substituting sprockets 96 and 9| for the gears 63 and 68, respectively, and a chain 92 for the idler gear 69. The sprocket 9| has one-half the number of teeth 'of the sprocket 90 and the chain 92 drivingly connects both sprockets. In al1 other respects, the drive may be of exactly the same construction as the drive shown in Figs. 5 and 6. It is evident that the modified drive shown in Fig. 7' performs in exactly the same manner as the drive shown `in Figs-5 and 6.

` The wide adaptability of the present drive is thus obvious, and it is for this reason that the present invention is not intended to be limited for use in sewing machines, this speciiied use being merely an example of the adaptability of the present invention.

` I claim:

l. `A drive comprising, in combination, a bar; a guide rotatable about an axis at right angles to the axis of the bar and guiding the latter for axial reciprocation; and a device operable to reciprocate t e bar in any position of the guide and including a direct connection with said bar so that the entire driving force transmitted through said connectionis always directed parallel to the bar axis, and means differently operating said device on rotation ofthe guide to move said connection angularly with the bar.

2. The combination in a drive as set forth in claim 1, wherein said connection with the bar is such that the entire driving force transmitted through said connection is always directed substantially coaxially of the bar.

3. In a drive of the type described, the combination of a bar; a member rotatable about its own axis; a guide rotating with theimember and g5 and a pivot connection between the element and' at right angles to the axis of said member and radially of the latter in any position of the guide; an element rotatable about its own axis which is parallel to that of the member and being bodily rotatable about the axis of said member and so drivingly connected with the latter at a two to one speed ratio as to be rotated about its own axis in one direction on being bodily rotated in the opposite direction relative to said member or on rotation of the latter in said one direction;

bar, said connection coaxially aligning with said member during rotation of said element about its own axis.

4. In a drive of the type described, the combination of a bar; avrst gear rotatable about its own axis; a guide rotating withthe gear and guiding the bar for axial reciprocation in a plane at right angles to the gear axis and radially of the latter in any position of the guide; a second gear rotatable about its own axis which is parallel to that of the first gear and being bodily rotatable about the axis of said rst gear and so drivingly connected with the latter at a two to one speed ratio as to be rotated about its own axis in one direction on being bodily rotated relative to said rst gear in the opposite direction' or on rotation of the latter in said one direction; and a pivot connection between said second gear and the bar, said connection coaxially aligning with said first gear during rotation of said second gear about its own axis.

5. The combination in a drive as set forth in claim4, in which the guide is provided with a laterally extending arm for oscillating said guide and said first gear. l

6. The combination in a drive as set forth in claim 4, in which said first gear is an internal gear and said second gear has external teeth and is in permanent mesh with the teeth of said internal gear.

7. The combination in a drive as set forth in claim 4, inwhich said gears have external teeth and are drivingly connected by intermediate gears whichare bodily rotated with said second gear. I 8. The combination in a drive as set forth in claim 4, in which said gears have external teeth and are drivingly connected by an idler gear which is bodily rotated together with said second gear, and the latter has one-half the pitch diameter of said first gear.

9. The combination in a drive as set forth in claim 4, in which said first gear is a ring gear with internal teeth and said second gear has external teeth and is in permanent mesh with the teeth of said internal gear, and said guide has a circular extension journalled on the outer periphery of said ring gear.

10. The combination in a drive as set forth in claim 4, in which said first gear is a ring gear with internal teeth and said second gear has external teeth and is in permanent mesh with the'teeth of said internal gear, and said guide areas-i4 teeth of said first sprocket and being rotatable about its own axis which is parallel to that of said first sprocket and bodily rotatable about the axis of said first sprocket; a chain connecting both sprockets; and a pivot connection between 5 said second sprocket and the bar, said connection coaxially aligning with said rst sprocket during rotation of said second sprocket about its own axis.

12. In a drive of the type described, the com: i0 y bination of a bar; an externally journalled sleeve having a crank at one end; means for driving said sleeve; a shaft journalled in said sleeve coaxially thereof; a first spur gear mounted on one end of said shaft adjacent said crank; a 15 second spur gear rotatably carried by said crank and having its axis parallel to that of said first gear and being so drivingly connected with the latter at a two to one speed ratio as to berotated about its own axis in one direction on rotation 20 of said crank in the opposite direction or on rotation of said first gear in said one direction;

a guide journalled coaxially of said sleeve and guiding the bar for axial reciprocation in a plane at right angles to the axis of said first gear and 25 radially of the latter in any position of the guide, said guide being connected with the other end of said shaft for combined rotation with said first gear; and a pivot connection between said second gear and the bar, said connection coaxial- 80 ly aligning with said rst gear during rotation of said second gear about its own axis.

13. The combination in a drive as set forth in claim l2, further comprising a bearing in which said sleeve is journalled, said bearing hav- 35 ing an external cylindrical surface on which said guide is journalled.

14. The combination in a drive as set forth in claim 12, in which said sleeve-driving means includes two meshing gears one of which is n mounted on the other end of said sleeve.

15. In a drive of the type described, the combination of a bar; an externally journalled sleeve having a crank at one end; means for driving. said sleeve; a shaft journalled in said sleeve coaxially thereof; a first sprocket mounted on one end of said shaft adjacent said crank; a second sprocket rotatably carried by said crank and having its axis parallel to that of said rst sprocket; a chain connecting said sprockets; a guide journalled coaxially of said sleeve and guiding the bar for axial reciprocation in a plane at right angles to the axis of said flrst sprocket and radi-- ally of the latter in any position of the guide, said guide being connected with the other end of said shaft for combined rotation withsaid first sprocket; and a pivot connection between said second sprocket and the bar, said connection coaxially aligning with said first sprocket during rotation of said second sprocket about its own axis, and said second sprocket having onehalf the number of teeth of said first sprocket.

16. In a drive of the type described, the combination of a bar; means for guiding said bar 55 for axial reciprocation; a non-rotating first spur gear having its axis extending at right angles to and intersecting the bar axis; a second spur gear rotatable about its own axis which is parallel to that of said first gear and being bodily rotatable about the axis of said first gear and so drivingly connected with thelatter at a two to one speed ratio as to be rotated about its own axis in one direction on being bodily rotated in the opposite direction.; and a pivot connec- 1| areas tion between said second gear and the bar, said connection coaxially aligning with said iirst gear during rotation of said second gear about its own axis.

17. In a drive of the type described, the combination of a bar; means for guiding said bar for axial reciprocation; a non-rotating rst sprocket having its axis extending at right angles to and intersecting the bar axis; a second 10 sprocket rotatable about its own axis which is parallel to that of said rst sprocket and being bodily rotatable about the axis of said first sprocket and having one-half the number of teeth of the latter; a chain connecting both sprockets; and a pivot connection between said second sprocket and the bar, said connection coaxially aligning with said first sprocket during rotation of said second sprocket about its own FRANKLIN A. REECE.

taxis. 

